The invention relates to a method for producing shaped bodies or for applying coatings on workpieces wherein it is to be dealt starting from well-known solutions which are known according to the term Rapid Prototyping, and herein in particular the laser beam precision type deposition welding. Thus, the invention can be used for the production of various three-dimensional shaped bodies with most different contoured surfaces, for example, and with cavities as well wherein undercuts can also be readily achieved. In addition, a relatively good finishing accuracy in the range of a few tenths of a millimeter can be ensured which requires slight finishing works only.
Another field of application for the invention is the formation of coatings on workpieces which are allowed to have particular contoured surfaces as well being up to surfaces realized in relatively filigreed manner. Thus, by the deposition of respective coatings, e.g. it is also possible to return worn-out or damaged surface areas of workpieces into the original state comprising the initial dimensions. Thus, both the wear related ablation and damages occurred due to overloads which have taken place are allowed to be balanced again.
In the recent past, different ways for the production of workpieces, for example, are known from DE 195 33 960 A1 among others in which the laser beam precision type deposition welding is employed. Then, such a three-dimensional workpiece is produced such that subsequently a three-dimensional formed body will be successively built up with a plurality of individual layers in a multilayered manner, which is differently dimensioned and formed inside the various layers. With this, a laser beam is respectively guided and formed such that supplied metal powder can be placed as single tracks, and can be molten on by means of a laser beam, and a layer having a plurality of parallel juxtaposed tracks can be formed within one plane, wherein a relatively good finishing accuracy can be achieved by obtaining very small widths and thicknesses of the track which will be increased by machining.
However, it is deleteriously with this well-known solution that the time consumed for producing such a workpiece is still relatively high in particular due to the relatively small achievable layer thicknesses in combination with the small track gauges. Another disadvantage is in that, on the one hand the efficiency is relatively small because of the laser beam used in combination with the absorption behaviour of the metal powder used. The last mentioned disadvantage will be further increased if during the formation of coatings on workpieces these are required to be preheated or reheating has to be implemented to maintain a particular temperature, since with this the laser beam used has to be defocussed, and thereby neither a second laser beam serving thereto has to be used nor an intermittent procedure including heating phases with the laser beam defocussed, and layer forming phases with the focussed laser beam are required which in turn involves an increase of the necessary time consumed.
Therefore, it is an object of the invention to propose a way wherein shaped bodies which are structured in an almost arbitrarily three-dimensional manner can be produced or contoured coatings on most different workpieces can be formed as well wherein simultaneously the required time and energy are reducible with respect to the conventional procedures.